Apparatus for cracking oil



Aug. 10, 1937. v p GUlCHARD 2,089,361

APPARATUS FOR CRACKING OIL Filed Jan. 30, 1935 2 Sheets-Sheet 1 [nrenfa'r fie/re Quickard.

7- P. GUICHARD 2089,36]

APPARATUS FOR CRACKING OIL Filed Jan. 30, 1955 2 Sheets-Sheet 2 Patented Aug. 10, 1937 lTE STATES 2&9361

ATENT OFFIQE Application January 30, 1935, Serial No. 4,188 In France February 2, 1934 8 Claims.

In the French patent specifications No. 711.623 relating to Process and apparatus for converting heavy hydrocarbons into hydrocarbons having a lower boiling point and No. 739.566 relating to Process and apparatus for the treatment of hydrocarbons, the inventor has described a process for the molecular conversion, under pressure and in the liquid phase, of hydrocarbons by passing these into two distinct zones, namely, a heat- 10 ing zone and a zone of reaction. In accordance with this process, a single stream of hydrocarbons heated to the desired temperature in the heating zone is, on its entry into the zone of reaction, divided up into several identical branch streams, which have been brought to a temperature which is adequate to the realization of the molecular conversion.

By the application of this process, this conversion can be carried out in a remarkable manner,

continuously and without the formation in the tubes of troublesome deposits of carbon.

The present invention relates to a process of the same kind, in which the molecular conversion, under pressure and in the liquid phase, of the hydrocarbons is likewise eiiected by the passage of these into two distinct zones, namely, a heating zone and a zone of reaction, the hydrocarbons passing in a single stream into the heating zone and the stream being divided up into branch streams in the zone of reaction. In accordance with the present invention, in the heating zone the hydrocarbons receive a quantity of calories which is sufficient to permit of their subsequent molecular conversion and, when in the zone of reaction, they are in an environment which is in thermal equilibrium with them, in such a manner that the molecular conversion takes place simultaneously in these various streams.

In accordance with a particularly interesting example of carrying out the present invention, the various branch streams circulating within the zone of reaction are placed under sets of physical conditions different from one another in such a manner that, in these various branch streams, the conversion can be efiected to a varying extent so that, in consequence, the products furnished by these various streams will differ from each other.

50 Thus, in accordance with the present invention,

in these various branch currents:-

(a) The quantities of hydrocarbons in circulation may differ from one another,

(1)) The speeds of circulation of the hydrocar- 55 icons may difier from one another,

(0) The cross-sections of the various branch streams may difier from one another, etc.

Numerous installations may be designed for the carrying out of the process described above.

The present invention has likewise as its ob- 5 ject the various installations which may be designed for the carrying out of the process described above or of the variants of the said process.

These installations are characterized by all or 10 part of the following elements:

(a) A single circuit for heating the hydrocarbons to their conversion temperature, which circuit may be formed by a heating coil receiving the hydrocarbons from a pipe under pressure and 15 which is arranged Within a heating chamber where all excessive heating is avoided,

(b) A feed-pipe connected to the outlet of the said coil,

(0) Tubes for the conversion of the hydrocarbons, these tubes being mounted in parallel on the said feed-pipe,

(d) Means for maintaining these tubes and their contents at the conversion temperature,

(6) An evaporator allocated to each tube,

(,1) A single fractionating tower to which there is connected the system of tubes for the passage of the vapours from each of the abovementioned evaporators,

(g) Each reaction tube is provided with means for disconnecting it from the circuit, with cleaning means, and with means for its restoration to the circuit, while the other tubes are in operation,

(h) Auxiliary reaction tubes.

(2) At least one of the tubes is provided with at least one of the following elements:

(00A by-pass for discharging into its evaporator after it has been placed out of circuit,

(5) A by-pass for filling and application of pressure before it is brought back into the circuit.

In accordance with one method of construction of an installation of this kind, several conversion tubes have capacities which diiier from one an other, and these differing capacities may be providedr- (a) Either by tubes which differ in diameter from each other, and are of equal length,

(12) By tubes having the same diameter and having lengths which differ from one another,

(0) By tubes having diameters which diiier from one another and lengths which difier from one another.

Moreover, at least one of the conversion tubes at W I8 I8, I8

is provided with members which permit the conditions of conversion of the hydrocarbons to be modified, which members may comprise all or part of the following elements: 5 (a) Pressure-reducing valve,

(b Means for the internal cooling of the hydrocarbons contained in this tube,

(0) Means for the external cooling of these same hydrocarbons. In accordance with other methods of construction by the present invention:

(a) The pressure-reducing valve of one reaction tube at least can be detached.

(2)) The evaporator belonging to this tube is provided with a pipe for drawing off the heavy products, a pipe for drawing off the products of medium densities and a pipe for the escape of the light products.

The accompanying diagrammatic drawings,

which illustrate examples of embodiment of the invention only and which are not intended to limit in any manner the scope of the invention, show:

Figure 1, in plan, an installation designed in accordance with the principles described above.

Figure 2, the same installation in elevation.

in both these figures the same reference characters refer to the same parts.

Referring to the drawings, I is the supply tank for the installation. This tank is connected by the pipe 2 to a mixing tank 3 which delivers, through a pipe 4, to a supply pump 5. This pump sends the hydrocarbons to be treated, at the desired pressure, through the pipe 6 into the heating M coil i. This heating coil '5 is placed in a heating chamber 8, which may be heated, for example, by burners fed with residual products, gaseous or non-gaseous, obtained by the treatment of the hydrocarbons in the installation. In this case,

4 this heating chamber is divided into two compartments 9, ill, by a partition H. In this heating chamber, the coil 1 is arranged in such a manner that the hydrocarbons to be treated are brought, at the point where they leave the heating 4 chamber, to a temperature which is sufficient for the conversion reaction, without itv being possible however for the hydrocarbons to be subjected at any point whatsoever to an overheating which might lead to the formation of deposits of carbon.

A feed-pipe is connected to the outlet of the coil 7. This feed-pipe l2 feeds by means of valves I3 I3 I3 lt the reaction tubes M li l4", M In Figure 1, these various reaction tubes M M M M are of lengths differing from one another and also of diameters differing from one another. The environment in thermal equilibrium with each reaction tube is formed in this case by an insulating lagging, the various insulating laggings being shown at lt l5 I5,

lt Each of these reaction tubes is provided with a pressure-reducing valve, which pressurereducing valves are shown at Ili lfi I 5, I (i as has been said, each of these pressure-reducing valves can be detached.

After each of these pressure-reducing valves there is mounteda low pressure valve, the various valves of this kind being marked W l'l l1, I'i In this way, with the aid of its high-pressure valve and its low-pressure valve, each tube can be separated from the rest of the installation, taken down, cleaned and put back or replaced by another.

An evaporator is arranged after each lowpressure valve; the various evaporators are shown Each of these evaporators Ili I8 l8 la is connected by a pipe l9 He l9", i to a common fractionating tower 20. This fractionating tower 20 is provided on its upper part with an outlet pipe 2| for the gaseous products and vapours, while draw-01f pipes 23 23 23, are arranged to correspond with various levels 22*, 22 22", in the tower. The medium products, such as the gas oils and the kerosenes, can be collected by means of these tubes. A pipe 24, which is arranged at the bottom part of this fractionating tower, enables those products to be discharged which have to be resubmitted to treatment. These products are led to the tank 3 by a pipe 25 with valve 25, while a pipe 26 with valve 26 enables a part of these products to be drawn to one side, when this is desired.

Each reaction tube is fitted with pyrometric control apparatus arranged close to its ends, for the purpose of enabling the course of the endothermic reaction which takes place there to be followed; these devices are diagrammatically indicated for the various tubes at Zi -28 21 28 Ti -48, El -28 In this case each tube is likewise provided with internal cooling devices. For this purpose, a pipe 29 starting from the tank I feeds a pump 3!], which through a pipe 3| feeds two feed-pipes, 32 and 33, on which there are mounted branches with valves 32*, 32* 32, 32 33 33*, 33, 33 which are respectively connected to the corresponding reaction tubes and provided with shut-ofi cocks. Branches 34 34 34, 34, mounted on the reaction tubes enable the oil under pressure contained in each of these tubes to be discharged into the corresponding evaporator by opening valves 35 35 35, 35

Each of these evaporators, the evaporator Ill for example, is likewise provided:-

(1) At its bottom part with a pipe 36 which enables the discharge of the residual oils to be effected,

(2) With a pipe 31 which enables a part of the oils, which has to be submitted again to the same treatment, to be drawn off.

Finally, a pipe 38, with valves 38*, 38 38, 38 serves as a by-pass between the pipe 6 and the reaction tubes and enables the pressures on the two sides of the high-pressure valve of each tube to be equalized before the opening of this latter Valve, the said pipe being, for this purpose, provided with branches connected to these various tubes.

An installation designed in this manner enables any product whatsoever of petroleum to be treated, as well as all the oils obtained from lowtemperature distillation, and enables the entire gamut of petroleum derivatives to be obtained.

Example-The supply tank I is filled with a parafiinic masut having a solidifying point of plus 38 C. The supply pressure of the pipe 5 is 32 kilos.

The temperature of the hydrocarbons, when they leave the heating chamber H, is 435 C. In one possible embodiment, the tubes M and M may have an equal length of 8 metres but different diameters, namely 50 mm. for the tube M and 65 mm. for the tube [d and the tube M may have a length of 12 metres and a diameter of 65 mm. Under these conditions, the reaction in tube M effects a weak reaction, so that there results a small quantity of light products and a large quantity of masut with a lowered solidifying point. The evaporator l8 retains a masut which has a solidifying point of plus 9 C. and the top of the evaporator delivers a gas oil which has a solidifying point of plus 5 C. In the tube M gas oil is produced. The evaporator 13 retains a masut which has a solidifying point of plus 3 C.; the top of the evaporator yields a gas oil with a solidifying point of C. The reaction in the tube M is a prolonged one and it enables .a larger percentage of kerosene and gasoline to be obtained. The corresponding evaporator retains residual oils having a solidifying point of minus 11 C. and a density of 1.060.

As in all fractionating columns, the tower 2E1 permits the drawing-off of the products on the plates. Petrol vapours and the gases pass through the pipe 2|.

The tube I i is a reserve tube which is intended to facilitate either a change of operations or the replacement of one of the tubes M W, M";

this tube being connected to the feed-pipe by a union, which permits the fitting on this feed-pipe of a tube M which may be identical with any one of the tubes I l M It, or it may be different from these.

Under the conditions described above, the times during which the hydrocabons brought into the zone of reaction remain there may be approximately as follows:

Time of remaining in the tube l 4 7 seconds.

Time of remaining in the tube Hl l20 seconds.

Time of remaining in the tube Hi -180 seconds.

What I claim is:--

1. In a plant for the conversion of hydrocarbons of high boiling points into hydrocarbons having lower boiling points in which the preheating of the hydrocarbons and the conversion are eifected substantially in the liquid phase and under pressure, a supply tank containing liquid hydrocarbons, means for feeding said hydrocarbons under pressure, a heating chamber having therein a heating coil for receiving said hydrocarbons, means for heating the said hydrocarbons in the said coil to conversion temperature, a manifold arranged outside said heating chamber and connected to said heating coil, a set of conversion tubes having diameters of the order of 65 millimeters, each of said conversion tubes constituting a complete separate individual path for the heated hydrocarbons, no one of said conversion tubes having the same length and cross-section as any other one of said conversion tubes, means for connecting each of the said conversion tubes to the said manifold, means for maintaining the hydrocarbons substantially in the liquid phase in the said conversion tubes, means for maintaining said tubes and their contents at the conversion temperature, means outside said conversion tubes for collecting the products delivered from said conversion tubes, means for recovering the converted products, and means for separating the unconverted products.

2. In a plant for the conversion of hydrocarbons of high boiling points into hydrocarbons having lower boiling points in which the preheating of the hydrocarbons and the conversion are effected substantially in the liquid phase and under pressure, a supply tank containing liquid hydrocarbons, means for feeding said hydrocarbons under pressure, a heating chamber having therein a heating coil for receiving said hydrocarbons, means for heating the said hydrocarbons in the said coil to conversion temperature, a manifold arranged outside said heating chamber and connected to said heating coil, a set of conversion tubes having diameters of the order of 65 millimeters, each of said conversion tubes constituting a complete separate individual path for the heated hydrocarbons, no one of said conversion tubes having the same length and crosssection as any other one of said conversion tubes, means for connecting each of the said conversion tubes to the said manifold, means for maintaining the hydrocarbons substantially in the liquid phase in the said conversion tubes, means for maintaining said tubes and their contents at the conversion temperature, an evaporator connected to each of said conversion tubes, a common fractionating tower connected to all said evaporators, escape piping for the gases from said evaporators connected to said fractionating tower, means for recovering the converted products, and means for separating the unconverted products.

3. In a plant for the conversion of hydrocarbons of high boiling points into hydrocarbons having lower boiling points in which the preheating of the hydrocarbons and the conversion are effected substantially in the liquid phase and under pressure, a supply tank containing liquid hydrocarbons, means for feeding said hydrocarbons under pressure, a heating chamber having therein a heating coil for receiving said hydrocarbons, means for heating the said hydrocarbons in the said coil to conversion temperature, a manifold arranged outside said heating chamber and connected to said heating coil, a set of conversion tubes having diameters of the order of 65 millimeters, each of said conversion tubes constituting a complete separate individual path for the heated hydrocarbons, no one of said conversion tubes having the same length and cross-section as any other one of said conversion tubes, means for connecting each of the said conversion tubes to the said manifold, means for maintaining the hydrocarbons substantially in the liquid phase in the said conversion tubes, means for maintaining said tubes and their contents at the conversion temperature, means for disconnecting each of said conversion tubes from said heating circuit while the other conversion tubes are in operation, means for reconnecting the said tube into said heating circuit while the other conversion tubes are in operation, means outside said conversion tubes for collecting the products delivered from said conversion tubes, means for recovering the converted products, and means for separating the unconverted products.

4. In a plant for the conversion of hydrocarbons of high boiling points into hydrocarbons having lower boiling points in which the preheating of the hydrocarbons and the conversion are effected substantially in the liquid phase and under pressure, a supply tank containing liquid hydrocarbons, means for feeding said hydrocarbons under pressure, a heating chamber having therein a heating coil for receiving said hydrocarbons, means for heating the said hydrocarbons in the said coil to conversion temperature, a manifold arranged outside said heating chamber and connected to said heating coil, a set of conversion tubes having diameters of the order of 65 millimeters, each of said conversion tubes constituting a complete separate individual path for the heated hydrocarbons, no one of said conversion tubes having the same length and crosssection as any other one of said conversion tubes, means for connecting each of the said conversion tubes to the said manifold, means for maintaining the hydrocarbons substantially in the liquid phase in the said conversion tubes, means for maintaining said tubes and their contents at the conversion temperature, a reserve conversion tube in parallel with the other conversion tubes and communicating with "said manifold, means outside said conversion tubes for collecting the products delivered from said conversion tubes, means for recovering the converted products, and means for separating the unconverted product.

5. In a plant for the conversion of hydrocarbons of high boiling points into hydrocarbons having lower boiling points in which the preheating of the hydrocarbons and the conversion are effected substantially in the liquid phase and under pressure, a supply tank containing liquid hydrocarbons, means for feeding said hydrocarbons under pressure, a heating chamber having therein a heating coil for receiving said hydrocarbons, means for heating the said hydrocarbons in the said coil to conversion temperature, a manifold arranged outside said heating chamber and connected to said heating coil, a set of conversion tubes having diameters of the order of 65 millimeters, each of said conversion tubes constituting a complete separate individual path for the heated hydrocarbons, no one of said conversion tubes having the same length and crosssection as any other one of said conversion tubes, means for connecting each of the said conversion tubes to the said manifold, means for maintaining the hydrocarbons substantially in the liquid phase in the said conversion tub-es, means for maintaining said tubes and their contents at the conversion temperature, a pressure reducing valve arranged on at least one of the said conversion tubes for enabling the conditions of the conversion in said tube to be modified, means outside said conversion tubes for collecting the prodducts delivered from said conversion tubes, means for recovering the converted products, and means for separating the unconverted products.

6. In a plant for the conversion of hydrocarbons of high boiling points into hydrocarbons having lower boiling points in which the preheating of the hydrocarbons and the conversion are effected substantially in the liquid phase and under pressure, a supply tank containing liquid hydrocarbons, means for feeding said hydrocarbons under pressure, a heating chamber having therein a heating coil for receiving said hydrocarbons, means for heating the said hydrocarbons in the said coil to conversion temperature, a man-- ifold arranged outside said heating chamber and connected to said heating coil, a set of conversion tubes having diameters of the order of 65 millimeters, each of said conversion tubes constituting a complete separate individual path for the heated hydrocarbons, no one of said conversion tubes having the same length and cross-section as any other one of said conversion tubes, means for connecting each of the said conversion tubes to the said manifold, means for maintaining the hydrocarbons substantially in the liquid phase in the said conversion tubes, means for maintaining said tubes and their contents at the conversion temperature, controllable cooling means provided on at least one of said tubes for decreasing the temperature of the hydrocarbons circulating therein, means outside said conversion tubes for collecting the products delivered from said conversion tubes, means for recovering the converted products, and means for separating the unconverted products.

7. In a plant for the conversion of hydrocarbons of high boiling points into hydrocarbons having lower boiling points in which the preheating of the hydrocarbons and the conversion are ber and connected to said heating coil, a set of conversion tubes having diameters of the order of 65 millimeters, each of said conversion tubes constituting a complete separate individual path for theheated hydrocarbons, no one of said conversion tubes having the same length and crosssection as any other one of said conversion tubes, means for connecting each of the said conversion tubes to the said manifold, means for maintaining the hydrocarbons substantially in the liquid phase in the said conversion tubes, means for maintaining said tubes and their contents at the conversion temperature, an evaporator connected to each of said conversion tubes, a single fractionating tower connected to all said evaporators, escape piping for the gases from said evaporators connected to said fractionating tower, means for recovering the converted products, means for separating the unconverted products, at least one of said evaporators having a tap positioned for drawing off the heavy products, a tap positioned for drawing off the products of medium density, and a tap positioned for drawing off the light products.

8. In a plant for the conversion of hydrocarbons of high boiling points into hydrocarbons having lower boiling points in which the preheating of the hydrocarbons and the conversion are eiiected substantially in the liquid phase and under pressure, a supply tank containing liquid hydrocarbons, means for feeding said hydrocarbons under pressure, a heating chamber having therein a heating coil for receiving said hydrocarbons, means for heating the said hydrocarbons in the said coil to conversion temperature, a manifold arranged outside said heating chamber and connected to said heating coil, a set of conversion tubes having diameters of the order of 65 millimeters, each of said conversion tubes constituting a complete separate individual path for the heated hydrocarbons, no one of said conversion tubes having the same length and cross-section as any other one of said conversion tubes, means for connecting each of the said conversion tubes to the said manifold, means for maintaining the hydrocarbons substantially in the liquid phase in the said conversion tubes, means for maintaining said tubes and their contents at the conversion temperature, an evaporator connected to each of said conversion tubes, a single fractionating tower connected to all said evaporators, escape piping for the gases from said evaporators connected to said fractionating tower, means for recovering the converted products, means for separating the unconverted products, at least one of said evaporators having a tap positioned for drawing oh the heavy products, a tap positioned for drawing on theproducts of medium density, a tap positioned for drawing off the light prod nets, and for at least one of said conversion tubes a by-pass connecting said conversion tube with its evaporator and permitting said conversion tube to be discharged into its evaporator after it has been disconnected from the heating circuit. PIERRE GUICHARD. 

